Defect-Engineered Dual-Mode synergistic CO2 Capture via Hydroxy-Rich CDs In-situ Confinement Reconstructing NH2-UiO-66 Adsorption-Diffusion Microenvironment

Metal-organic frameworks (MOFs) offer exceptional pore tunability for targeted separations. Moving beyond conventional defect engineering which often sacrifices selectivity for permeability, we propose to construct functionalized defects that synergistically integrate hierarchical low-resistance gas transfer pathways with tailored ultra-CO 2 -philic molecular domains. This strategy is achieved by in-situ embedding β-cyclodextrin (β-CD) as a multifunctional modulator during the crystallization of NH 2 -UiO-66 (NUiO). The macrocyclic cavities of β-CD induced structural defects cooperatively optimize the pore architecture of NH 2 -UiO-66, significantly enhancing gas permeability. Concurrently, exposed Zr 6 clusters and hydroxyl groups from β-CD enhance CO 2 adsorption capacity. Furthermore, defect-induced incomplete coordination promotes hydrogen bonding between the β-CD@NUiO and Pebax, improving interfacial compatibility for MMMs. The prepared β-CD 20 @NUiO MMM at 5 wt.% filler loading exhibits a CO 2 permeability of 125.5 Barrer and a CO 2 /N 2 selectivity of 112.4, exceeding the 2019 McKeown upper bound. The in-situ construction of defects via functional molecules transcends the limitations of single-parameter optimization for mass transfer pathways and active sites in porous materials, establishing a universal design principle for multifunctional coupled separation materials.